Any good team worth their salt will recognize that those with siloed information on the team are a threat to productivity to everyone else. People should get hired and kept based on their ability to learn, their approach to problem-solving, and their ability to share knowledge and unshackle their coworkers from any dependencies on oneself. If a coworker in my organization had disproportionate value stemming from a cache of undocumented information (meaning that then writing documentation would make them disposable), then they’re not worth having in the long run.

A smart manager would start finding someone to receive that knowledge and the smart employee would volunteer to learn. Giving raises to the person with the siloed information to incentivize them to work and share information with other employees is a relatively inexpensive cost to the alternative of spending a yearly salary on someone who’s main draw is being a walking notion/confluence page